You eat out at restaurants and fast-food joints because it’s quick and easy. But a new study found that you’re exposing yourself to a potentially harmful chemical in the process.

The study, which was published in the journal Environmental International, used data from the National Health and Nutrition Examination Survey (NHANES) collected between 2005 and 2014. More than 10,000 people participated in the study and were asked to recall what they ate and where their food came from in the past 24 hours, as well as to give urine samples. The researchers found that people who ate at restaurants, cafeterias, and fast-food joints were more likely to have elevated levels of potentially harmful chemicals called phthalates in their body than those who didn’t.